The present invention relates to an agricultural working machine with a moisture content sensor arrangement for measuring a moisture content of picked-up crop and generating a crop moisture signal based on the measured moisture content.
Agricultural working machines, which include self-propelled harvesting machines such as combine harvesters, customarily comprise diverse working devices that can be operated with fluctuating parameters during the processing of crop. The setting of these parameters is referred to as a machine parameter setting. In order to ensure optimal operation, the machine parameter setting should be set depending on various basic conditions, including, in particular, the type, amount, and condition of the stand in the field and/or the crop.
In fact, one significant basic condition is the moisture content of the crop in the crop stream as a whole, which is determined substantially via the moisture content of the straw, i.e., the straw moisture content. An accurate determination of the moisture content of the crop is very helpful for an optimal setting of the machine parameters.
It is known from the prior art to determine the moisture content of the grain material after the grain material has been separated from the rest of the crop. However, the moisture content of the grain material does not always provide sufficiently precise information on the moisture content of the crop since this is not typically the determining variable for the moisture content of the crop.
From document EP 1 576 869, it is known to determine the moisture content of the crop using a moisture sensor disposed in the feeder housing of a combine harvester. In this manner, it is possible to determine and react to the moisture content of the crop continuously and nearly simultaneously with the pick-up of the crop by the agricultural working machine.
The disadvantage of this prior art is that the measurement of the moisture content can be inaccurate, especially when the moisture sensor is designed as a capacitive sensor. This is due to the fact that such a sensor substantially measures and determines the entire quantity of water that moves past the sensor. However, this total quantity of water is dependent not only on the relative moisture content of the crop, but also on the entire quantity of crop that was picked up at the time of the measurement. As a result, the moisture content that is measured is often falsified upward when the crop throughput is relatively high, and is falsified downward when the crop throughput is low.
Proceeding from this prior art, the problem addressed by the invention is that of developing an agricultural working machine such that a highly accurate determination of the moisture content in the crop is even more accurate.